Mobile devices typified by mobile cellular phones have been designed so as to be capable of making use of various application programs, such as JAVA® applications. Users can download application programs from a server to the mobile devices and execute various operations including data communications with arbitrary servers.
Such application programs may includes bugs, and in fact, many cases have been reported where abnormal data transmission has occurred due to freezing or hang-up (endless iterations) of application programs caused by bugs and resulting in meaningless data transmission, or where a huge amount of data communication fees are billed to users. As long as it is established that the factors of such errors reside on the side of the venders offering the application programs, the vendors may bear the communication fees. However, if such errors are caused by unknown reasons, communication fees are likely to be charged to individual users. This problem is becoming a social issue.
Japanese Patent Laid-open Publication No. 8-125779 discloses a system for preventing a high amount of fees from being imposed on users in LAN access from a LAN device to a network (e.g., ISDN). In this publication, if “invalid access”, such as endless repetition of a specific pattern file continues over a prescribed time period designated by a user, the connection is automatically cut off.
Another publication, Japanese Patent Laid-open Publication No. 2000-32176 also discloses a method for preventing a high amount of communication charges from being billed to a user. In this publication, every time a line is disconnected, the communication fee is stored and accumulated. If the accumulated amount of data communication fees reaches a prescribed amount set per month by the user, no more data communication is allowed in that month.
The techniques disclosed in both publications can prevent a high amount of fees from being charged to users; however, the transmission control is performed only at the user devices. Accordingly, users have to purchase particular hardware or software and set parameters, such as “time” or “amount”, by themselves.
In addition, depending on information type, there may be data items that users do not want to stop transmission of even if the communication fee exceeds the prescribed level, and for other data items, users may want to cut off the connection at an earlier stage. The prior art techniques disclosed in the above-described publications perform only a fixed control, and cannot deal with flexible control according to information types.
Another problem of the prior art techniques in which communication control solely relies upon user devices is that if abnormal transmission is caused by bugs contained in an application program downloaded from a server, there are no means for reporting the bugs or the abnormal transmission. This means that appropriate measures (such as modification of the program) are delayed.